Mufp 0603 12z Ford Stroker Engine Building

After the valves have been faced, they need to be lapped to the seat. Marvin likes a nice compromise on valve-seat contact. Here, we see that .060 inch of the valve face is the intake valve contact point, good for cylinder sealing, valve cooling, and airflow. For an ideal balance of street and strip, opt for .090 inch for better heat transfer. This is especially critical to valve life.